1. Physics 496 Michael Atkinson
Holographic Storage
Physics 496
Michael Atkinson

2. Why Holographic Storage?
Storage Density
media stores data in whole volume
Speed
parses many bits at once
Reliability
Good shelf life
High number of write cycles
Michael Atkinson

3. Outline Holography Concepts Refractive index modulation Storing data
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4. Types of Holograms Transmission Hologram Reflection Hologram
Can be used to store data
Uses coherent light
Reflection Hologram
The kind you find on credit cards
Uses white light
Michael Atkinson

5. Holography vs Photography
Black and white photograph
Intensity
Color photograph
Intensity and wavelength
Hologram
Intensity, phase, and sometimes wavelength
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6. Review of Interference
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7. Creating Hologram
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8. Pattern Left on Media
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9. Reconstructing the Image
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10. Qualitative Explanation of Storage
Reference beam
Object image
Resultant pattern
Stored in film
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11. Qualitative Explanation of Reconstruction
Reflection
Reference beam
Stored in film
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12. Photorefractive effect
Electrons gain energy from light
Leave Valence band, can move freely
Diffuse toward dark areas
When beams removed, electrons settle and we have internal net electric fields
Index of refraction changed due to electro-optic effect
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13. Intensity Threshold EConduction EValence External electric field
Object Image
Reference Beam
Object Image
Reference Beam
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14. Storing Data
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15. Reading Data
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16. Current State of Technology
Storage
CD-ROM: 800 Mbytes – 10 cents
DVD+DL: 8.4 Gbytes - $3
Blu-Ray DL: 50 Gbyte - $30
InPhase Tapestry: 300 Gbyte - $250
Hard disk: 1 Tbyte - $300
HVD (future): 4 Tbytes
Transfer rates
CD-ROM 52x: ~ 5 Mbit/second
DVD 16x: ~ 20 Mbit/s
InPhase Tapestry: 20 Mbit/sec
Blu-Ray and HDDVD: ~ 30 Mbit/sec
7200 rpm Hard disk: 80 Mbit/sec
Michael Atkinson

17. References
Physics for Scientists and Engineers with Modern Physics – Vol 2, Serway and Jewett
International Conference on Holography, Optical Recording, and Processing of Information:
Thermally sensitized optical recording in azobenzene polymers
D.Illieva, M. Ivanon, T. Petrova, V. Dragostinova, G. Minchev, T. Todorov, L. Nikolova
Refractive data of optical plastics for laser applications
N. Sultanova, S. Kasarova, C. Ivanov, I. Nikolov
Pulse Recording Dynamics of Diffraction Gratings in Xanthene Dyes Sensitized Photopolymer Material
E. Vasilyev, V. Shelkovnikov, E. Pen, A. Plechanov
Holographic recording in nanoparticle-doped photopolymer
I. Naydenov, H. Sheriff, S. Mintova, S. Toala
Michael Atkinson

18. Image Sources Slide 2: ad from slashdot.com Slide 6:
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Slide 10:
drawn by me
Slide 11:
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taken from Thermally sensitized optical recording in azobenzene polymers, D.Illieva, M. Ivanon, T. Petrova, V. Dragostinova, G. Minchev, T. Todorov, L. Nikolova
Slide 14:
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Slide 19:
Michael Atkinson

19. Questions?
Michael Atkinson